*{
    margin: 0;
    padding: 0;
}

body{
    background-image: url("背景图片1.jpg");
    background-repeat: no-repeat;
    background-size: 100%;
    padding-top: 50px;
    font-size: 15px;
    color: rgb(60,4,112);

    /* 弹性布局 让页面元素水平+垂直居中 */
    display: flex;
    justify-content: center;
    align-items: center;
    /* 让页面始终占浏览器总高 */
    height: 100vh;
}

img{
    width: 100%;
    height: 100%;
}



#side-menu {
    background-color: lightgrey;
    display: block;
    position: fixed;
    top: 0px;
    left: 0px;
    bottom: 0px;
    width: 250px;
    transition: transform 200ms ease-in;
    transform: translateX(calc(-100% + 24px));
}

#side-menu:hover {
    transform: translateX(0px);
}

#side-menu-inner {
    display: block;
    height: 100%;
    width: calc(100% - 24px);
    background-color: rgb(72, 67, 67);
}





.a1{
    text-align: center;
    top:100%;
    margin: 20px auto;
    height: 800px;
}

.father{
    display: inline-block;
    position: relative;
    padding: 10px 20px;
    background-color: palevioletred;
}

.son{
    display: none;
    position: absolute;
    background-color: pink;
    top:40px;
    left:10px;
    padding:5px;
}
.son>li{
    padding: 5px;
}
.son>li:hover{
    background-color: palevioletred;
    color:crimson;
}

.father:hover .son{
    display: block;
}

a:visited{
    color:purple;
}


.c1{
    width:1190px;
    /* 弹性布局 让元素均匀排列 */
    display: flex;
    justify-content: space-around;
}

.c1 li{
    position:relative;
    width:300px;
    height:300px;
    overflow: hidden;
    margin: 0 10px;
}

.c1 li:hover{
    cursor: pointer;
}

.mask{
    position: absolute;
    top:100%;
    height: 100%;
    width: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;

    background: #464646e8;
    color:#fff;

    transition:all .7s ease-out;
}

.c1 li:hover .mask{
    top:0;
}

.mask h1{
    line-height: 50px;
}
.mask p{
    padding: 20px;
    font-weight: 500;
    word-break: break-all;
}

li{
    list-style: none;
}


a{
    text-decoration: none;
}



            

